http://messenger.msn.com/support/firewall.asp“To enable the use of MSN Messenger Service: Open outgoing TCP Port 1863, and configure it so that sockets on this port are open for extended periods of time.”“To enable the use of AOL Instant Messenger (AIM) integration with MSN Messenger Service (Windows only): Open outgoing TCP Port 5190, and configure it so that sockets on this port are open for extended periods of time.”I presume the trigger is the same port as the service uses 1863 for inbound and outbound packets (http://support.microsoft.com/default.aspx?scid=kb;EN-US;q277812). Larry

I think my problem is I'm connected to the internet using an SMC router connected to a Cisco ADSL router.Since it does work - can anyone help me figure out how to get messenger to file transfer. I can do file transfers within the home network using messenger - but not outside on the web.

I have tried various combinations of using 1863 as a trigger port - opening ports 6891-6900 which messenger uses for file transfer - still no go

I did not intend to have cascading routers. I assume my Internet provider used just straight DSL modems. So I purchased the SMC router in order to share the Internet connection & have a home networking all in one. When I noticed I had problems with file transfers with Messenger – I started to investigate possible causes.I happen to look up the modem that I have – presto – ADSL router modem.Since I have the equipment – I would like to try and make it work – If not I will install a network switch

One post on the same problem is suffucient in these forums. I do not, however, have an answer to this particular problem and do not believe there is one that is an adequate solution at this time. Larry

My NAT (Network Address Translation) Router will not work with the MSN Messenger's File transfer or Voice connections.

S O L U T I O N

As explained on Microsoft's support page, Client computers that use a NAT router are not able to use MSN, The Microsoft Network Messenger Service version 3.0 program to transfer files or establish voice connections. This problem occurs because MSN Messenger file transfer and voice features do not work through NAT routers because there is no NAT editor to correctly translate the IP header information.

This is MSN Messenger's software limitation. Linksys Routers will not be able to bypass this until an appropriate NAT editor is available.

THe one thing that will work with the Linksys router is to set the DMZ host to your computer's IP address. The DMZ Host setting can be found under the Advanced tab of the configuration utility. This will allow all packets sent to the router to be redirected to your computer (normaly they are just dropped), and is basicly the same thing as plugging your computer directly into the DSL/Cable modem. Though personaly i would not do this, since it is extremely unsecure, especialy if you are running web server software.